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<head><meta charset="utf-8"><title>Potential very small breakage by qualifying panic · t-libs · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/index.html">t-libs</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html">Potential very small breakage by qualifying panic</a></h3>

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<a name="215021370"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021370" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021370">(Oct 29 2020 at 20:12)</a>:</h4>
<p><a href="https://github.com/rust-lang/rust/pull/78343">https://github.com/rust-lang/rust/pull/78343</a> qualifies the call to <code>panic!()</code> from <code>assert_eq!()</code>, <code>todo!()</code>, etc. with <code>$crate</code>, fixing a hygiene bug they had where they might call a shadowed <code>panic!()</code> defined by the user. it is technically a breaking change, but really just a hygiene bugfix. I'm tempted to just <code>r+</code> it. how careful should we be with situations like this?</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021398" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021398">(Oct 29 2020 at 20:12)</a>:</h4>
<p>cc <span class="user-mention" data-user-id="307537">@Camelid</span></p>



<a name="215021570"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021570" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021570">(Oct 29 2020 at 20:14)</a>:</h4>
<p>IMO code that hypothetically relied on being able to shadow panic there is just going to need to be fixed. We could do a crater run before merging to see what the breakage looks like but it seems obscure enough that I think it'd just be fine to merge. If we're wrong, the beta crater runs should pick it up anyway</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021816" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021816">(Oct 29 2020 at 20:16)</a>:</h4>
<p>I suspect most of the cases where people are overriding panic! won't be caught by crater anyway</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021869" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021869">(Oct 29 2020 at 20:17)</a>:</h4>
<p>they're likely to either be on embedded targets or a difference between "my custom message" and "just panic!" which crater can't detect</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021895" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021895">(Oct 29 2020 at 20:17)</a>:</h4>
<p>It seems like most of the situations are in performance-critical code: <a href="https://grep.app/search?q=%5E%5Cs%2Amacro_rules%21%20panic%20%7B&amp;regexp=true&amp;case=true&amp;filter[lang][0]=Rust">https://grep.app/search?q=%5E%5Cs%2Amacro_rules%21%20panic%20%7B&amp;regexp=true&amp;case=true&amp;filter[lang][0]=Rust</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021902" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021902">(Oct 29 2020 at 20:17)</a>:</h4>
<p>I sort of can't imagine someone overriding a panic! with something that's non-panicky</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021928" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021928">(Oct 29 2020 at 20:17)</a>:</h4>
<p>craterbot's queue is a bit long at the moment.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215021995" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215021995">(Oct 29 2020 at 20:18)</a>:</h4>
<p>yeah i did that search. posted the three cases that might break in the PR here: <a href="https://github.com/rust-lang/rust/pull/78343#issuecomment-718970335">https://github.com/rust-lang/rust/pull/78343#issuecomment-718970335</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022104" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022104">(Oct 29 2020 at 20:19)</a>:</h4>
<p>(almost all results there are just (old) copies of core or std)</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022113" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022113">(Oct 29 2020 at 20:19)</a>:</h4>
<p>All those crates will have to do is just also shadow assert/assert_eq, right?</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022144" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022144">(Oct 29 2020 at 20:19)</a>:</h4>
<p>yup. or just switch to using #[panic_handler] instead.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022243" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022243">(Oct 29 2020 at 20:20)</a>:</h4>
<p>Yeah, then I'd just land it and cc the authors of those repos so they have some heads up</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022284" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022284">(Oct 29 2020 at 20:20)</a>:</h4>
<p>the only case i found in a crate that seems to be in use is a testcrate in our own compiler-builtins</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022308" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022308">(Oct 29 2020 at 20:20)</a>:</h4>
<p>alright. r+'ing it.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022386" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022386">(Oct 29 2020 at 20:21)</a>:</h4>
<p>I do see that boringssl seems to rely on shadowing <code>panic!</code> to produce a compile error: <a href="https://github.com/google/mundane/blob/master/src/boringssl/abort.rs#L96">https://github.com/google/mundane/blob/master/src/boringssl/abort.rs#L96</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022432" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022432">(Oct 29 2020 at 20:21)</a>:</h4>
<p>but they override all the other macros too. looks like they explicitly do not want to rely on this hygiene bug</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022514" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022514">(Oct 29 2020 at 20:22)</a>:</h4>
<p>Ah, yes, I missed that. Alright, seems good then!</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022519" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022519">(Oct 29 2020 at 20:22)</a>:</h4>
<p>(only they missed <code>todo!()</code>)</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022540" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022540">(Oct 29 2020 at 20:22)</a>:</h4>
<p>Well <code>todo!</code> is more recent</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022559" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022559">(Oct 29 2020 at 20:22)</a>:</h4>
<p><span class="user-mention" data-user-id="307537">@Camelid</span>  oh wait, you still wanted to squash the commits right, before i r+ it?</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022561" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022561">(Oct 29 2020 at 20:22)</a>:</h4>
<p>The file hasn't been updated since Dec 2018</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215022576" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215022576">(Oct 29 2020 at 20:22)</a>:</h4>
<p>Oh yes, thanks! I forgot :)</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215023187" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215023187">(Oct 29 2020 at 20:28)</a>:</h4>
<p>Squashed <span aria-label="smile" class="emoji emoji-1f642" role="img" title="smile">:smile:</span></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215023347" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215023347">(Oct 29 2020 at 20:30)</a>:</h4>
<p><span class="user-mention" data-user-id="310399">@Mara</span> Should I add a test for <code>unreachable!</code> too?</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215023588" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215023588">(Oct 29 2020 at 20:31)</a>:</h4>
<p>might be good, if you have the time</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215023659" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215023659">(Oct 29 2020 at 20:32)</a>:</h4>
<p>i can imagine you feel like you have already spent enough time on this change ^^'</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215024273" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215024273">(Oct 29 2020 at 20:37)</a>:</h4>
<p>It was much more involved than I thought, but also very interesting :)</p>



<a name="215024282"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215024282" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215024282">(Oct 29 2020 at 20:37)</a>:</h4>
<p>About to push up a commit</p>



<a name="215024344"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215024344" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215024344">(Oct 29 2020 at 20:38)</a>:</h4>
<p>(Just waiting on a build)</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215025465" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215025465">(Oct 29 2020 at 20:47)</a>:</h4>
<p>Done</p>



<a name="215025668"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215025668" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215025668">(Oct 29 2020 at 20:49)</a>:</h4>
<p><span class="user-mention" data-user-id="310399">@Mara</span> Do you want to mark as <code>rollup=never</code> so it's easier to bisect if there are issues?</p>



<a name="215025698"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215025698" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215025698">(Oct 29 2020 at 20:49)</a>:</h4>
<p>Might not be necessary but wanted to suggest it</p>



<a name="215025931"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215025931" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215025931">(Oct 29 2020 at 20:51)</a>:</h4>
<p>I don't think that's necessary. Any issues this might create should directly point at the macro name and <code>panic!()</code>. Should be easy to find.</p>



<a name="215026503"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215026503" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215026503">(Oct 29 2020 at 20:55)</a>:</h4>
<p>Sounds good.</p>



<a name="215049534"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215049534" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215049534">(Oct 30 2020 at 02:01)</a>:</h4>
<p>(And I feel like there's a general overuse of never lately -- it gives the PR higher priority, so the other day when I tried to use <code>rollup=iffy</code> it just never landed between all the <code>always</code> stuff and the rollups that get p=5.  So I'll just never use <code>iffy</code> again...)</p>



<a name="215049710"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215049710" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215049710">(Oct 30 2020 at 02:04)</a>:</h4>
<p>Well it's frustrating when a rolled-up PR introduces a regression because it can be hard to tell which rolled-up PR caused it</p>



<a name="215049936"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215049936" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215049936">(Oct 30 2020 at 02:09)</a>:</h4>
<p>Yeah, no easy answers here.</p>



<a name="215051220"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215051220" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Noah Lev <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215051220">(Oct 30 2020 at 02:36)</a>:</h4>
<p>Except for adding more compute power <span aria-label="smile" class="emoji emoji-1f642" role="img" title="smile">:smile:</span></p>



<a name="215155567"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215155567" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215155567">(Oct 30 2020 at 21:58)</a>:</h4>
<p><span class="user-mention" data-user-id="307537">@Camelid</span> not sure if you noticed, but your PR failed in CI because apparently two tests have an unused <code>use std::panic;</code> that only became actually unused with your bug fix.</p>



<a name="215432438"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/219381-t-libs/topic/Potential%20very%20small%20breakage%20by%20qualifying%20panic/near/215432438" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Yoshua Wuyts <a href="https://rust-lang.github.io/zulip_archive/stream/219381-t-libs/topic/Potential.20very.20small.20breakage.20by.20qualifying.20panic.html#215432438">(Nov 03 2020 at 10:03)</a>:</h4>
<p>(deleted)</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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